LOCATION ROOSTERCOMB             OR

Established Series
Rev. MHF/TDT
01/2023

ROOSTERCOMB SERIES

The Roostercomb series consists of moderately deep, well
drained soils on tops and side slopes of hills. They formed
in colluvium from greenstone. Slopes are 2 to 50 percent.
The mean annual precipitation is about 14 inches and the
mean annual temperature is about 42 degrees F.

TAXONOMIC CLASS: Clayey-skeletal, smectitic, frigid Typic Argixerolls

TYPICAL PEDON: Roostercomb extremely gravelly clay loam, on
a 45 percent south-facing slope, rangeland. (Colors are for
moist soil unless otherwise noted.)

A1--0 to 5 inches; dark brown (10YR 3/3) extremely
gravelly clay loam, brown (10YR 4/3) dry; moderate very fine
and fine subangular blocky structure; slightly hard,
friable, slightly sticky and slightly plastic; many very
fine and fine roots; many very fine and fine tubular pores;
50 percent gravel, 10 percent cobbles and 5 percent stones;
neutral (pH 6.6); clear smooth boundary. (4 to 8 inches
thick)

A2--5 to 12 inches; dark brown (10YR 3/3) extremely
gravelly clay loam, brown (10YR 5/3) dry; moderate fine and
medium subangular blocky structure; slightly hard, firm,
sticky and plastic; common very fine and fine and few medium
roots; many very fine and fine tubular pores; 60 percent
gravel and 5 percent cobbles and stones; neutral (pH 6.8);
clear smooth boundary. (5 to 12 inches thick)

Bt1--12 to 25 inches; dark yellowish brown (10YR 4/4)
extremely gravelly clay, light yellowish brown (10YR 6/4)
dry; moderate medium and coarse subangular blocky structure;
hard, firm, sticky and plastic; common very fine and fine
and few medium roots; many very fine and fine tubular pores;
common moderately thick clay films on ped faces and lining
pores; 60 percent gravel and 5 percent cobbles and stones;
neutral (pH 7.0); gradual wavy boundary. (6 to 13 inches
thick)

Bt2--25 to 36 inches; dark yellowish brown (10YR 4/6)
extremely cobbly clay, light yellowish brown (10YR 6/4) dry;
moderate coarse subangular blocky structure; very hard, very
firm, very sticky and very plastic; few fine roots; common
very fine and fine tubular pores; many moderately thick clay
films on ped faces and in pores; 30 percent cobbles, 25
percent gravel and 10 percent stones; neutral (pH 7.2);
gradual wavy boundary. (5 to 12 inches thick)

R--36 inches; highly fractured greenstone.

TYPE LOCATION: Baker County, Oregon; located in the NW1/4SE1/4NE1/4SE1/4 of sec. 24, T. 12 S., R. 41 E.

RANGE OF CHARACTERISTICS: These soils are usually moist,
but are dry between depths of 4 and 12 inches for 45 to 90 consecutive days following the summer solstice. The mean
annual soil temperature is 42 to 47 degrees F. Depth to
bedrock is 20 to 40 inches. The solum is neutral or mildly
alkaline. The thickness of the mollic epipedon and depth to
the Bt horizon is 10 to 20 inches.

The A1 horizon has value of 2 or 3 moist, 3 through 5 dry
and chroma of 2 or 3 moist and dry. It has 40 to 50 percent
gravel, 5 to 10 percent cobbles and 0 to 10 percent stones.

The A2 horizon has value of 3 or 4 moist, 4 or 5 dry and
chroma of 2 or 3 moist and dry. It is clay loam or loam
with 25 to 35 percent clay. It has 40 to 60 percent gravel
and 5 to 10 percent cobbles and stones.

The Bt horizon has value of 4 or 5 moist, 5 or 6 dry and
chroma of 4 or 6 moist and dry. It is silty clay or clay,
with 40 to 50 percent clay. It has 55 to 80 percent rock
fragments. Cobbles and stones are more dominant in the
lower horizons.

The Bk horizon, when present, has value of 5 or 6 moist, 6
or 7 dry and chroma of 3 or 4 moist and dry. It is loam or
clay loam, averaging 20 to 30 percent clay. It has 10 to 20
percent gravel and 40 to 60 percent cobbles and stones.

COMPETING SERIES: These are the Birchcreek, Derringer,
Erakatak, Leevan, McIvey, Ravenswood, Yago and Yeates
Hollow. McIvey, Yago and Yeates Hollow soils are over 40
inches deep. Leevan soils have less than 55 percent rock
fragments in the argillic horizon. Ravenswood and
Birchcreek soils have mollic epipedons that include the
upper part of the Bt horizon. Derringer soils have a
paralithic contact at a depth of 20 to 40 inches. Erakatak
soils have a paralithic contact at a depth of 20 to 35
inches which overlies a lithic contact an A horizon less
than 4 inches thick and a mollic epipedon which includes the
upper part of the argillic.

GEOGRAPHIC SETTING: Roostercomb soils are on stable to
meta-stable side slopes of hills. Elevations range from
3,800 to 5,700 feet. Slope is 2 to 50 percent. The soils
formed in colluvium from greenstone. The mean annual
precipitation is 12 to 16 inches. The mean annual
temperature is 40 to 45 degrees F. The frost-free period is
50 to 90 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Ateron,
Durkee and Longbranch soils. Ateron soils are 10 to 20
inches deep and are clayey-skeletal. Durkee soils are fine
and have a calcic horizon. Longbranch soils are 40 to 60
inches deep and the mollic epipedon is over 20 inches thick.

DRAINAGE AND PERMEABILITY: Well drained. Runoff is slow to
rapid. Permeability is slow.

USE AND VEGETATION: These soils are used for rangeland and
wildlife habitat. The native vegetation is mainly mountain
big sagebrush, threetip sagebrush, wild crab apple, antelope
bitterbrush, Idaho fescue, bluebunch wheatgrass and Sandberg bluegrass.

DISTRIBUTION AND EXTENT: East central and northeastern
Oregon. The soils are of moderate extent.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon

SERIES ESTABLISHED: Baker County Area, Oregon; 1988.

REMARKS: Diagnostic horizons and features in this pedon
are:

Mollic epipedon - the zone from the surface of the soil to a
depth of approximately 12 inches (A1, A2 horizons).

Argillic horizon - the zone from approximately 12 to 36
inches (Bt1, Bt2 horizons).

Typic feature - mollic epipedon to a depth of between 10 and
20 inches.

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National Cooperative Soil Survey
U.S.A.